1. Field of the Invention
The illustrative embodiments relate generally to a valve for controlling fluid flow therethrough and, more specifically, to a valve having a flap that is disposed between two plates and capable of movement between an open and closed position.
2. Description of Related Art
Conventional valves typically operate at lower frequencies below 500 Hz for a variety of applications. For example, many conventional compressors typically operate at 50 or 60 Hz. A linear resonance compressor known in the art operates between 150 and 350 Hz. Such pumps are typically relatively large, and produce audible noise in operation. However, many portable electronic devices including medical devices require pumps for delivering a positive pressure or providing a vacuum that are relatively small in size and it is advantageous for such pumps to be inaudible in operation so as to provide discrete operation.
To achieve the objectives of small size, high efficiency, and inaudible operation, certain pumps (such as that described in International Patent Application No. PCT/GB2006/001487, published as WO 2006/111775) must operate at very high frequencies, in turn requiring valves that must operate at very high frequencies to be effective. Such pumps require valves capable of operating at much higher frequencies of around 20 kHz and higher which are not commonly available. To operate at these high frequencies, the valve must be responsive to a high frequency oscillating pressure that can be rectified to create a net flow of fluid through the pump.
A valve for controlling the flow of fluid that is capable of operating at such higher frequencies is disclosed. The valve comprises a first valve plate having apertures extending generally perpendicular therethrough and a second valve plate also having apertures extending generally perpendicular therethrough, wherein the apertures of the second valve plate are substantially offset from the apertures of the first valve plate. The valve further comprises a sidewall disposed between the first and second valve plates, wherein the sidewall is closed around the perimeter of the first and second valve plates to form a cavity between the first and second valve plates in fluid communication with the apertures of the first and second valve plates. The valve further comprises a flap disposed and moveable between the first and second valve plates, wherein the flap has apertures substantially offset from the apertures of the first valve plate and substantially aligned with the apertures of the second valve plate. The fabrication and handling of the valve plates may be facilitated by the use of certain lead-frame technology for the construction of the valve.